Infertility

Introduction

Infertility is a condition when conception does not take place even after one year of regular, unprotected sexual intercourse. It can affect either the male or female. It can be due to a variety of factors including endocrine disorders, defects in the reproductive systems, deficient production of sperms or eggs, drugs and toxic chemicals, childhood diseases such as mumps, etc. There has been a recent increase in the number of infertility cases reported throughout the world.





Cause and Pathogenesis

Infertility is caused due to a multitude of factors both in the male and the female. In the male, a low sperm count or defective spermatozoa is a major factor. Another common factor that contributes to male infertility is the presence of a varicocele, which is a cluster of enlarged veins around the testicle. Varicocele elevates temperature in this part of the body by increasing blood circulation and the higher temperature reduces sperm production. Defects in the male reproductive tract can also be responsible for infertility. Childhood disorders such as mumps may result in permanent damage of the reproductive organs, leading to infertility. The use of certain drugs and toxic chemicals can contribute to infertility. In females, Pelvic Inflammatory Disease (PID) is the major cause of infertility throughout the world. PID covers a wide variety of infections that can affect the uterus, ovaries, and fallopian tubes. The sites of infection that usually cause infertility are the fallopian tubes, the inflammation of which produces a condition known as salpingitis.

Most infections are caused by sexually transmitted diseases. Chlamydia trachomatis is an infectious organism that causes a large proportion of salpingitis cases. Gonorrhea is responsible for much of the rest. Attacks of PID can eventually cause scarring, abscess formation, and tubal damage that result in infertility. Endometriosis is responsible for a substantial proportion of cases. It results when fragments of the endometrial lining are implanted in other areas of the pelvis, which then develop into cysts and respond to hormonal changes, increasing in size with each menstrual cycle and eventually causing scarring and inflammation. Endometrial implants in the ovaries or fallopian tubes are especially prone to cause infertility. Ovulatory and hormonal problems are responsible for almost 30% of infertility cases in women. These problems result in the failure of the ovarian follicle to rupture, an empty follicle, or entrapment of the egg so that it is not released. Polycystic Ovarian Syndrome (PCO) occurs in 6% of women and is also major cause of infertility.

Some cases of unexplained infertility may result from early loss of ovarian function. Immune system failure can also cause infertility. Scar tissue that forms after abdominal surgery can restrict the movement of ovaries, fallopian tubes, or the uterus and may cause infertility. Other causes of infertility include a ruptured appendix, diabetes, kidney disease, thyroid disorders, hypertension, drugs, and toxic chemicals.





Symptoms and Signs

Among normally fertile couples, one half will conceive by three months, 75 percent by six months, and 90 percent by one year. Infertility can be said to be present in either the male, the female or both partners if there is no conception even after one year of regular, unprotected sexual intercourse. Approximately 30-40 percent cases of infertility are due to male factors such as low sperm count or varicocoele in the testicles, 50-60 percent of infertility cases are due to ovulation problems, pelvic disease, and to cervical problems in the female. About 5-10 percent of cases have no known cause. If the couple has already had a child or two, it is not unusual to have difficulty conceiving again. Such secondary infertility is more common than primary infertility. The same factors may be involved, advancing age could be the most significant.





Investigations and Diagnosis

In the male, sperm examination and sperm count is commonly done. As male factors contribute to more than a third of infertility problems, a semen analysis is necessary as part of the evaluation. A specimen of semen is examined microscopically in the laboratory, to determine the number of sperms as well as their size, shape, and motility. If the sample proves normal, no further tests may be necessary for the male. If there are less than 60 million sperm per cubic centimetre, less than 60 percent normal forms, or less than 60 percent actively moving sperm, or any other abnormalities in the sperm, further evaluation is indicated. Examination of the reproductive tract and genital organs may be necessary.

In females, the basal body temperature is recorded each morning over several months to find any ovulatory disorders. Other methods to confirm ovulation include a blood test to measure progesterone blood level after ovulation and a biopsy of the lining of the uterus. Blockages of the tubes or abnormalities in the uterine lining, may require a hysterosalpingogram (HSG). A dye is injected through the cervix into the uterine cavity and tubes, and an X ray photograph is taken. The outline of the lining of the uterus is examined to confirm that the tubes are normal and open. A postcoital test (PCT) may be done shortly after intercourse to evaluate the cervical mucus and its interaction with the sperm. Laparoscopy may be done to visualise the abdominal and pelvic cavity to see the uterus, fallopian tubes and ovaries, to detect pelvic adhesions, scarring, endometriosis or other relevant pathology.





Treatment and Prognosis

If there is no ovulation or if the ovulation is not regular, drugs can be given to stimulate ovulation. The most common drug is clomiphene, the fertility pill. This safe, effective drug stimulates the ovaries to produce ova. Other treatments include fertility shots, such as human Menopausal Gonadotropin (hMG), and a drug that stimulates the pituitary gland - Gonadotropin-releasing Hormone (GnRH). Surgery is used to correct any defects of the reproductive tract, both in the male and female.

In vitro fertilisation and embryo transfer (IVF-ET) and gamete intrafallopian transfer (GIFT) are recently introduced treatments. With IVF-ET, the ovaries are stimulated with drugs to produce several ripe eggs at the same time. The eggs are then removed, usually under local anaesthesia, using ultrasound to guide a catheter through the vagina into the abdominal cavity. The eggs are incubated under special conditions and then the sperm is added. Fertilisation occurs in the laboratory, resulting in a test-tube baby. Next, several of the pre-embryos are placed through the cervix into the uterine cavity. This improves the chance of success but also increases the chances of a multiple pregnancy.

With GIFT, the ovaries are stimulated with drugs, but the eggs are removed using a laparoscope. At the same time, a mixture of eggs and sperm is placed into the fallopian tubes. Open fallopian tubes are necessary for GIFT, but not for IVF-ET. If extra pre-embryos are formed after removing the eggs and processing them, the pre-embryos are sometimes frozen and later transferred into the uterus during future cycles. Another recently developed treatment is intracytoplasmic sperm injection, which only requires one sperm to achieve a pregnancy. These treatments can be used for cases in which the male sperm count is very low, the woman has endometriosis or in cases of unexplained infertility. The success rates for the recently discovered therapeutic modalities are improving. Counselling and psychotherapy is also essential in the treatment of infertility.

Prevention


Causative factors of infertility, if known, can be avoided. Immunisation must be given in childhood to prevent diseases such as mumps that affect the reproductive organs. Toxic drugs and chemicals that affect the reproductive tract must be avoided. Prompt treatment of pelvic infections is necessary to prevent permanent damage to the reproductive organs.